Abstract:To detect doxycycline (DC) residues in aquatic products,a ciELISA method were developed through preparing monoclonal antibody (McAb) by immunizing BALB/C mice,using doxycyline-bovine serum albumin conjugate (DC-BSA) as immunogen.The BALB/C mice used in the experiment for cell fusion were selected by two methods,the indirect ELISA and the indirect competitive ELISA.A hybridoma cell strain (3D1-H4),which can secret a McAb that specifically reacted with DC,were obtained.The McAb was separated by using hybridoma technology,and it was identified to belong to IgG1 by the indirect ELISA.A ciELISA for detecting DC was then developed,using this McAb.This McAb was characterized on its sensitivity,IC50 and veracity.The results showed that the titers of the McAb were 1∶(8×102) and 1∶(5.12×105) in supernatant and ascites,respectively.This McAb had 8.87%,5.86% and 2.74% cross-reactivity with tetracycline,oxytetracycline and chlotetracycline,respectively.The linear detection range for this ciELISA varied from 1.58 to 199.53 ng/mL,with a sensitivity of 2.88 ng/mL and an IC50 of 36.31 ng/mL.The recoveries of DC spiked in fish muscle and liver were 85.13% and 79.69%,respectively.Both the inter-assay and intra-assay coefficient variations were less than 15%.These results suggested that this ciELISA method was able to be used for detecting DC residues in aquatic products.